Alghamdi Turki, Aina Peter O, Rownaghi Ali A, Rezaei Fateme
Linda and Bipin Doshi Department of Chemical and Biochemical Engineering, Missouri University of Science and Technology, Rolla, Missouri 65409-1230, United States.
Department of Chemistry, Cleveland State University, 2121 Euclid Ave., Cleveland, Ohio 44115, United States.
ACS Appl Mater Interfaces. 2023 Jul 19;15(28):33621-33632. doi: 10.1021/acsami.3c05821. Epub 2023 Jul 7.
Metal-organic frameworks (MOFs) often exhibit an exceptional adsorption-based separation performance for a variety of gases, ions, and liquids. While most radioactive iodine removal studies focus on the capture of radioactive iodine from off-gas streams, few studies have systematically investigated the effect of structure-property relationships of MOFs on iodine removal performance in the presence of interfering ions in liquid solutions. Herein, we investigated the iodide ion (I) adsorption performance of two model MOFs (e.g., Ni-MOF-74 and Zr-UiO-66) in liquid phase as a function of iodine concentration (e.g., 0.125 to 0.25 and 0.50 mmol/L) and adsorption temperature (e.g., 25 to 40 and 60 °C), and in the presence of interfering ions such as Cl and CO through batch-mode experiments. Under identical experimental conditions, Ni-MOF-74 outperformed Zr-UiO-66 in immobilizing iodine from the solution by achieving a maximum iodine removal efficiency of 97% at 60 °C. The results showed that the presence of other interfering ions marginally affects the iodine removal efficiency (e.g., capacity and rate of iodine capture) over both MOF adsorbents. The adsorption kinetics was found to be controlled by multiple transport processes encompassing external surface adsorption, intraparticle diffusion, and final equilibrium. Moreover, the leach test results revealed 8 and 12% iodine release from Ni-MOF-74 and Zr-UiO-66, respectively, at 25 °C after 48 h aging. This study establishes guiding principles for sustainable removal of iodine in the presence of Cl and CO species in cyclohexane.
金属有机框架材料（MOFs）通常对多种气体、离子和液体表现出基于吸附的卓越分离性能。虽然大多数放射性碘去除研究集中于从废气气流中捕获放射性碘，但很少有研究系统地研究MOFs的结构-性能关系对液体溶液中存在干扰离子时碘去除性能的影响。在此，我们通过间歇式实验研究了两种典型MOFs（即Ni-MOF-74和Zr-UiO-66）在液相中碘离子（I）的吸附性能，该性能是碘浓度（如0.125至0.25和0.50 mmol/L）和吸附温度（如25至40和60 °C）的函数，且是在存在诸如Cl和CO等干扰离子的情况下。在相同实验条件下，Ni-MOF-74在从溶液中固定碘方面优于Zr-UiO-66，在60 °C时实现了97%的最大碘去除效率。结果表明，其他干扰离子的存在对两种MOF吸附剂的碘去除效率（如碘捕获容量和速率）影响甚微。发现吸附动力学受多种传输过程控制，包括外表面吸附、颗粒内扩散和最终平衡。此外，浸出试验结果显示，在25 °C下老化48小时后，Ni-MOF-74和Zr-UiO-66分别有8%和12%的碘释放。本研究为在环己烷中存在Cl和CO物种的情况下可持续去除碘建立了指导原则。
